/*
 * Copyright ${inceptionYear} - ${year} ${owner}
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package jetbrains.exodus.util;

/**
 * StringBuilderSpinAllocator reuses StringBuilder instances performing non-blocking allocation and dispose.
 */
public class StringBuilderSpinAllocator {

    private StringBuilderSpinAllocator() {
    }

    private static class Creator implements SpinAllocator.ICreator<StringBuilder> {
        @Override
        public StringBuilder createInstance() {
            return new StringBuilder();
        }
    }

    private static class Disposer implements SpinAllocator.IDisposer<StringBuilder> {
        @Override
        public void disposeInstance(final StringBuilder instance) {
            instance.setLength(0);
            if (instance.capacity() > 4096) {
                instance.trimToSize();
            }
        }
    }

    private static final SpinAllocator<StringBuilder> allocator =
            new SpinAllocator<>(new Creator(), new Disposer(), 100);

    public static StringBuilder alloc() {
        return allocator.alloc();
    }

    public static void dispose(final StringBuilder instance) {
        allocator.dispose(instance);
    }
}
